Because of an increasing need to balance health risks for pathogen control and disinfection byproduct
(DBP) formation in water supplies, utilities are forced to closely examine and optimize their disinfection
practices. The authors provide a simple mechanistic model to predict total trihalomethane (TTHM)
and the sum of nine haloacetic acids (HAA9) formation based on chlorine demand. To evaluate this
modeling approach, eight Missouri surface waters (raw and alum-treated) were used in DBP
formation and chlorine decay kinetic studies. A parallel first-order reaction model was used to fit the
chlorine decay data, and the model coefficients were used to predict THM and HAA formation.
Yield coefficients for TTHMs and HAA9 were obtained from fitting the DBP kinetic data. On average,
the TTHM and HAA9 yield coefficients for all raw surface waters tested were about 40 ug TTHM/mg
Cl2 and 25 ug HAA9/mg Cl2 consumed, respectively. In waters subjected to alum coagulation, the
average TTHM and HAA9 yield coefficients were 30 ug TTHM/mg Cl2 and 17 ug HAA9/mg Cl2
consumed, respectively. The DBP predictive model introduced in this study provided a simple,
reliable basis to evaluate treatment options by focusing on chlorine demand. This model can be
readily calibrated to local conditions. Includes 23 references, tables, figures.
| Edition : | Vol. 94 - No. 10 |
| File Size : | 1
file
, 250 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 11 |
| Published : | 10/01/2002 |
